Sewing machine



FIG. 1 is a front perspective view of a sewing machine showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left end view thereof; and

FIG. 7 is a right end view thereof. 

The ornamental design for a sewing machine, substantially as shown and described. 